Anchor bolts, which may be welded, or otherwise fastened, to the reinforcing-bars and/or cages, are typically anchored in concrete-footings or mounting-blocks, pads or slabs, (hereinafter referred to as “a concrete slab”), to enable the mounting of infrastructure, such as portal frames, light-posts, street-signs; or machinery, such as engines, motors, supports for conveyors; or the like.
Typically, the anchor bars are arranged in one or more pairs in a pre-arranged pattern, in the concrete slab, to align with the holes/recesses in the base plate(s) of the infrastructure/machinery to be mounted thereon.
It is not always possible to ensure that the anchor bolts will be accurately located before the concrete is poured; or will not be bent, or otherwise dislocated, before the installation of the infrastructure/machinery.
It is typical, therefore, to provide a recess, such as an annular space, around at least an upper portion of each anchor bolt that would otherwise be embedded in the concrete slab. This enables one or more of the anchor bolts in a pattern to be “deflected” into alignment with respective holes/recesses in the base of the infrastructure/machinery.
After the anchor bolt(s) have been so aligned, the recesses are usually filled with grout, or other cementitious material, to the level of the underside of the infrastructure/machinery and the surrounding top surfaces of the concrete slab.
Typically the prior art blockouts employed to form the recesses are manufactured “on-site”, being cut from lengths of expanded-polystyrene tubes, which have an internal bore substantially equal to the outer diameter of the anchor bolts. The blockouts are cut to length; and are typically shaped to the desired external shape using knives, or other shaping tools; and are then typically wrapped in “duct tape”, to limit the ingress of water from the surrounding cementitious mix, as the concrete is poured and at least partially-set.
When the concrete has at least partially set, each blockout must be dug out of, or destroyed in and removed from, its respective recess, e.g., by using scrapers or like hand-tools to expose the recess.
Not only is this time consuming e.g., typically taking 10 to 15 minutes for the production and removal of each blockout; but the method is particularly messy, with polystyrene pieces/shavings being spread around the worksite, both when the individual blockouts are cut and shaped from the parent tubes; and then when the blockouts are dug out from their recesses. The polystyrene pieces/shavings may affect the workers' breathing, and can be slippery under foot, providing a work-place occupational health and safety (OH&S) hazard; and also an environmental hazard to adjacent waterways and the like.
A “vacuum cleaner”, or like suction apparatus with a collection bag, should preferably be employed to clean the worksite of the polystyrene pieces/shavings.
Finally, each blockout is manufactured for use on a once-only basis; and is therefore wasteful of the polystyrene materials and the transport required from the factory (or warehouse) to the site.